?? This is not in the Constitution.
Article 1, Section 5, 3rd paragraph (emphaiss mine):
"Each House shall keep a journal of its proceedings, and from time to time publish the same, excepting the parts as may in their judgement require Secrecy; and the Yeas and Nays of the members of either House on any question shall, at the Desire of one fifth of those Present, be entered on the Journal"